1. Field of Invention
This invention relates in general to propulsion systems, and more particularly to outboard propulsion systems for water vehicles.
2. Description of the Related Art
Various propulsion systems have been proposed and implemented for different boats and particularly boats having planing type hulls. Numerous outboard engines have been developed with a series of holes and movable pins to provide for the adjustment of the thrust line angle which is known to provide improved performance in propulsion systems. Different inboard/outboard propulsion systems have employed complex electro-hydraulic systems and electromechanical systems to adjust the thrust line angle for improved performance. Additionally, the inboard/outboard propulsion systems have employed a series of holes and movable pins used with hydraulic power trim systems for adjusting the thrust line angle for improved performance. Tilt cylinders have also been used in the past. In jet propulsion systems, there were significant limitations in adjustment means, utilizing either a manual adjustment or a power adjustment. Typically, as part of a jet propulsion system, a complex and cumbersome electro-hydraulic and electro-mechanical system were employed for adjusting the thrust angle for improved performance.
Utilized in prior attempts was the knowledge that the efficiency of a jet propulsion system is related to the size of the nozzle. Large nozzles allow a maximum flow rate of water which results in maximized propulsion efficiency. Also recognized was that a reduced nozzle size minimizes the tendency to cavitate which can cause a serious loss of performance at lower speed ranges, i.e. 5 to 22 miles per hour. A conventional nozzle is generally arranged to minimize the size of the nozzle and the flow rate of water to prevent cavitation. The cavitation failure resulted in greater fuel consumption, more engine noise and greater wear and tear on the engine.
Water jet propulsion systems have been disclosed in the following U.S. Patents:
U.S. Pat. No. 3,336,752 issued to M. S. Smith on Aug. 22, 1967;
U.S. Pat. No. 3,283,737 issued to C. A. Gongwer on Nov. 8, 1966;
U.S. Pat. No. 3,212,258, issued to C. A. Gongwer on Oct. 19, 1965;
U.S. Pat. No. 3,575,127 issued to G. F. Wislicenus on Apr. 13, 1971.
The applicant of the present invention Waldo E. Rodler has two prior patents U.S. Pat. Nos. 3,809,005 and 4,073,257 related in part to the present disclosure. U.S. Pat. No. 3,809,005 discloses a shield or deflector for reversing the direction thrust included an annular configuration and a series of arc-shaped forward jet ports which produced an essentially annular jet. Such annular jets were not totally effective in clearing foreign matter entrained in the water about the intake duct. The deflector was not fully effective in controlling reverse water flow. U.S. Pat. No. 4,073,257 was an improved propulsion system where a jet propulsion system used a spring to control the angle or tilting of the thrust and use of a hydraulic cylinder between a tilt stop and a mounting bracket.
Accordingly, it is the primary object of this invention to provide an improved outboard jet propulsion system with a horizontal crankshaft engine utilizing a belt or chain transfer drive. The present invention also discloses a two nozzle outboard system using the aforementioned belt or chain transfer drive, height adjustment system, thrust angle vector positive and automatic control, water lubricated bearings, and a vented pulley which reduces pumping power losses, and which is highly efficient, safe, and quiet during operation.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentality's and combinations particularly pointed out in the appended claims.